Replacement of olivine by serpentine in the Queen Alexandra Range 93005 carbonaceous chondrite (CM2): Reactant–product compositional relations, and isovolumetric constraints on reaction stoichiometry and elemental mobility during aqueous alteration

Velbel, M. A.; Tonui, E.; Zolensky, M. E.

doi:10.1016/j.gca.2014.10.007

Cited by 31 publications

(58 citation statements)

References 92 publications

(296 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In general, the models are broadly consistent with one another, and for a summary, the reader is referred to table in Velbel et al. (). In the following paragraphs, we describe how the bulk modal mineralogy of CM chondrites changes with alteration and discuss where the CM1s fit into the current models.…”

Section: Discussionsupporting

confidence: 58%

“…For example, Velbel et al. () showed how excess Fe leached from chondrules during late‐stage aqueous alteration could be incorporated into sulfide rims surrounding the resulting pseudomorph. They identified Fe‐sulfide rims in QUE 93005, but not around comparable pseudomorphs in the CM chondrites ALH 81002 and Nogoya, suggesting that there were discrete geochemical environments where the availability and/or mobility of S differed.…”

Section: Discussionmentioning

confidence: 99%

“…After all other materials were hydrated, the last phases to be altered were the coarse Mg‐rich olivines and pyroxenes in chondrules and isolated fragments (Hanowski and Brearley ; Velbel et al. , ). In some highly altered CM2s, coarse anhydrous silicates are partially hydrated, with the liberated Fe combining with S to form Fe‐sulfides at the margins of pseudomorphs (Velbel et al.…”

Section: Discussionmentioning

confidence: 99%

“…In some highly altered CM2s, coarse anhydrous silicates are partially hydrated, with the liberated Fe combining with S to form Fe‐sulfides at the margins of pseudomorphs (Velbel et al. ). Type 1 aqueous alteration was reached when any remaining coarse Mg‐rich olivine and pyroxene were hydrated, leaving CM chondrites consisting of abundant phyllosilicate (84–91 vol%), magnetite, and Fe‐sulfide.…”

Section: Discussionmentioning

confidence: 99%

See 3 more Smart Citations

Type 1 aqueous alteration in CM carbonaceous chondrites: Implications for the evolution of water‐rich asteroids

King

Schofield

Russell

2017

Meteorit & Planetary Scien

110

View full text Add to dashboard Cite

Abstract-The CM carbonaceous chondrite meteorites experienced aqueous alteration in the early solar system. They range from mildly altered type 2 to almost completely hydrated type 1 chondrites, and offer a record of geochemical conditions on water-rich asteroids. We show that CM1 chondrites contain abundant (84-91 vol%) phyllosilicate, plus olivine (4-8 vol%), magnetite (2-3 vol%), Fe-sulfide (<5 vol%), and calcite (<2 vol%). The CM1/2 chondrites contain phyllosilicate (71-88 vol%), olivine (4-20 vol%), enstatite (2-6 vol%), magnetite (2-3 vol%), Fe-sulfides (1-2 vol%), and calcite (~1 vol%). As aqueous alteration progressed, the abundance of Mg-serpentine and magnetite in the CM chondrites increased. In contrast, calcite abundances in the CM1/2 and CM1 chondrites are often depleted relative to the CM2s. The modal data support the model, whereby metal and Fe-rich matrix were the first components to be altered on the CM parent body(ies), before further hydration attacked the coarser Mg-rich silicates found in chondrules and fragments. Based on the absence of tochilinite, we suggest that CM1 chondrites experienced increased alteration due to elevated temperatures (>120°C), although higher water/rock ratios may also have played a role. The modal data provide constraints for interpreting the composition of asteroids and the mineralogy of samples returned from these bodies. We predict that "CM1-like" asteroids, as has been proposed for Bennu-target for the OSIRISREx mission-will have a high abundance of Mg-rich phyllosilicates and Fe-oxides, but be depleted in calcite.

show abstract

Section: Discussionsupporting

confidence: 58%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Type 1 aqueous alteration in CM carbonaceous chondrites: Implications for the evolution of water‐rich asteroids

King

Schofield

Russell

2017

Meteorit & Planetary Scien

110

View full text Add to dashboard Cite

show abstract

“…In the probe mount (JW-1-E), we identified many chondrules that were completely altered to phyllosilicates. Glassy mesostasis and metal were among the first components in chondrules to react with the fluids, before continued alteration started to replace the coarser Mgrich olivine and pyroxene grains (Hanowski and Brearley 2001;Velbel et al 2012Velbel et al , 2015. Chondrules that are entirely hydrated are typically found in the most altered CM chondrites (CM2.0; Rubin et al 2007).…”

Section: Microscale Propertiesmentioning

confidence: 99%

The alteration history of the Jbilet Winselwan CM carbonaceous chondrite: An analog for C‐type asteroid sample return

King

Russell

Schofield

et al. 2018

Meteorit & Planetary Scien

View full text Add to dashboard Cite

Jbilet Winselwan is one of the largest CM carbonaceous chondrites available for study. Its light, major, and trace elemental compositions are within the range of other CM chondrites. Chondrules are surrounded by dusty rims and set within a matrix of phyllosilicates, oxides, and sulfides. Calcium‐ and aluminum‐rich inclusions (CAIs) are present at ≤1 vol% and at least one contains melilite. Jbilet Winselwan is a breccia containing diverse lithologies that experienced varying degrees of aqueous alteration. In most lithologies, the chondrules and CAIs are partially altered and the metal abundance is low (<1 vol%), consistent with petrologic subtypes 2.7–2.4 on the Rubin et al. () scale. However, chondrules and CAIs in some lithologies are completely altered suggesting more extensive hydration to petrologic subtypes ≤2.3. Following hydration, some lithologies suffered thermal metamorphism at 400–500 °C. Bulk X‐ray diffraction shows that Jbilet Winselwan consists of a highly disordered and/or very fine‐grained phase (73 vol%), which we infer was originally phyllosilicates prior to dehydration during a thermal metamorphic event(s). Some aliquots of Jbilet Winselwan also show significant depletions in volatile elements such as He and Cd. The heating was probably short‐lived and caused by impacts. Jbilet Winselwan samples a mixture of hydrated and dehydrated materials from a primitive water‐rich asteroid. It may therefore be a good analog for the types of materials that will be encountered by the Hayabusa‐2 and OSIRIS‐REx asteroid sample‐return missions.

show abstract

Asteroid bombardment and the core of Theia as possible sources for the Earth's late veneer component

Sleep

2016

Geochem Geophys Geosyst

View full text Add to dashboard Cite

The silicate Earth contains Pt-group elements in roughly chondritic relative ratios, but with absolute concentrations <1% chondrite. This veneer implies addition of chondritelike material with 0.3-0.7% mass of the Earth's mantle or an equivalent planet-wide thickness of 5-20 km. The veneer thickness, 200-300 m, within the lunar crust and mantle is much less. One hypothesis is that the terrestrial veneer arrived after the moon-forming impact within a few large asteroids that happened to miss the smaller Moon.Alternatively, most of terrestrial veneer came from the core of the moon-forming impactor, Theia. The Moon then likely contains iron from Theia's core. Mass balances lend plausibility. The lunar core mass is ~1.6×10 21 kg and the excess FeO component in the lunar mantle is 1.3-3.5×10 21 kg as Fe, totaling 3-5×10 21 kg or a few percent of Theia's core. This mass is comparable to the excess Fe of 2.3-10×10 21 kg in the Earth's mantle inferred from the veneer component. Chemically in this hypothesis, Fe metal from Theia's core entered the Moon-forming disk. H 2 O and Fe 2 O 3 in the disk oxidized part of the Fe, leaving the lunar mantle near a Fe-FeO buffer. The remaining iron metal condensed, gathered Pt-group elements eventually into the lunar core. The silicate Moon is strongly depleted in Pt-group elements. In contrast, the Earth's mantle contained excess oxidants, H 2 O and Fe 2 O 3 , which quantitatively oxidized the admixed Fe from Theia's

show abstract

Replacement of olivine by serpentine in the Queen Alexandra Range 93005 carbonaceous chondrite (CM2): Reactant–product compositional relations, and isovolumetric constraints on reaction stoichiometry and elemental mobility during aqueous alteration

Cited by 31 publications

References 92 publications

Type 1 aqueous alteration in CM carbonaceous chondrites: Implications for the evolution of water‐rich asteroids

Type 1 aqueous alteration in CM carbonaceous chondrites: Implications for the evolution of water‐rich asteroids

The alteration history of the Jbilet Winselwan CM carbonaceous chondrite: An analog for C‐type asteroid sample return

Asteroid bombardment and the core of Theia as possible sources for the Earth's late veneer component

Contact Info

Product

Resources

About